<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .father {
            width: 300px;
            height: 300px;
            background-color: pink;

            /* padding-top: 50px; */
            /* overflow: hidden; */
        }
        .son {
            width: 100px;
            height: 100px;
            background-color: skyblue;

            margin-top: 50px; 
            /* 此操作会导致把父级标签也拉下来 */
            
            /* 为了解决此“塌陷”操作 */
            display: inline-block;
        }
    </style>
</head>
<body>
    <div class="father">
        <div class="son">Son</div>
    </div>
</body>
</html>